Earth Perihelion 4 January 2026
On the morning of Sunday 4 January, Earth is at its closest distance to the Sun for the year. The path of Earth around the Sun is not a perfect circle, but slightly oval-shaped. In early January each year, Earth is closest to the Sun, at a time known as perihelion, while in early July it is at its furthest from the Sun, at a time known as aphelion. The variation in distance between perihelion and aphelion is approximately 3%.
As perihelion occurs at the height of the Australian summer, that could suggest that it causes the seasons. It does not, as is obvious by the consideration that the Northern Hemisphere summer occurs at aphelion. However, the perihelion in January does make the southern summer a little hotter than otherwise and, more importantly, shorter, for the closer Earth is to the Sun, the faster it is moving.
Relief is at hand though, as perihelion will not always occur in January. There are year-to-year fluctuations, but perihelion occurs a day later every 58 years, on average, due to the phenomenon of precession. So, if we wait for about 10,000 years, which is a short time in astronomical terms, perihelion will occur during the northern summer. Then it will be the turn of the people in the north to cope with slightly hotter and shorter summers.
The seasons are, in fact, mainly due to the 23.5° tilt of the axis of Earth as it moves around the Sun. It is summer in the Southern Hemisphere when that half of Earth is tilted towards the Sun. Six months later, Earth is on the other side of the Sun and tilted so that it is summer in the Northern Hemisphere.
